Stencils

[John80]

Hello!

I was looking for a stencil manufacturer the other day and found a few good services. I thing the best out there (with a good value for money) is from Eurocircuits. The stencil is a metal type and cut by laser compared to iTead ones that are chemically etched. On the other hand PCBCart is now offering stencils but they are not showing any info about the type of the stencils or the cost. I've sent them a mail a few weeks ago but no response since then.

Have you got any stencil advise (metal ones and not Kapton or Mylar)? Any previous experience, manufacturers name or even photos? Something in the scale of 70Euros or even less, preferably, for a 30x20cm... and not the ones from 100+ scale

[senso]

iTead Studios offer framed stencils, here:
http://iteadstudio.com/service/pcb-smt-stencil-service-and-pcba-service/

[Short Circuit]

Last lasercut from PcbCart was $88+$27 for a simple straight stencil.
Etched stencils have better cost, especially for high pincount. Last order was E51+E11.22

(Both stencil + shipping, for some reason sometimes they quote in USD, other times in EUR).

When I only need a quick stencil (under 1000pads), then I usually resort to Beta Layout  https://www.laser-stencil.com/lsuk/info_stencilpool.html
57 euro incl VAT

[mikeselectricstuff]

PCBtrain's "Express laser stencil service" is the cheapest I know for stainless stencils in the UK. www.pcbtrain.com

www.smtstencil.co.uk for polyester.
 

[John80]

@mikeselectricstuff
I've never used polyester stencils before or to be accurate I have used only metal ones. What about the quality of the polyester stencils? Have you tried before? Any picture with small pitch high pin count components? From previous blog topics I know that they wear really easily over time.

@Short Circuit
I was hopping that PCBCart will be cheaper for the laser ones...

@senso
I know iTead studio and they are pretty good for small stencils. But if you repeat your PCB two times in the X axis and 4 at the Y axis (or even more) then then cost is growing up fast.

[mikeselectricstuff]

I have done 0.5mm qfps with plastic but wouldn't reccommend it.
I'd say above 0.65mm pitch, and pcbs below about 100x100 they're fine for 10-20 uses, so good for prototypes but not production
 

[Short Circuit]

@Short Circuit
I was hopping that PCBCart will be cheaper for the laser ones...

If it helps; I have used quite a few of their etched stencils without problem, including stencils with high pad count (>3000) and 0.4mm pitch LQFP.

Regardless which stencil technology, you must be very carefull with PcbCart stencil preproduction approval.
They tend to heavily modify pads and remove things like fiducials. But special pads such as pin-in-paste often go down the drain too.

[John80]

If it helps; I have used quite a few of their etched stencils without problem, including stencils with high pad count (>3000) and 0.4mm pitch LQFP.

Well, that helped a lot!!!

Regardless which stencil technology, you must be very carefull with PcbCart stencil preproduction approval.
They tend to heavily modify pads and remove things like fiducials. But special pads such as pin-in-paste often go down the drain too.

Ok, I will be careful. I will try to place my first stencil order with PCBCart an a couple of weeks. For I just sent them another mail with a few questions about shipping costs, stencil specs etc

[jtacek]

We are Polish laser cut stencil manufacturer.
www.semicon.com.pl
Please send us your file.
We are interested in if our quote wiil be close to your expectation...
We can offer also stencils streched on the Al frame
Jacek

[tinhead]

We are Polish laser cut stencil manufacturer.
www.semicon.com.pl
Please send us your file.
We are interested in if our quote wiil be close to your expectation...
We can offer also stencils streched on the Al frame
Jacek

Jacek,

i don't mind but it would be better if your website would really support multilanguage, currently - when i select english - is just a mix of everything

[Rundstedt]

I'll hijack this thread a bit. How do one design stencils? Or maybe one just send gerber files and manufacturer takes care of the rest?

I've never worked near smt line but will probably need to set up one in April.

[poorchava]

That depends entirely on toolchain that designer is using and complexity of design. For simple designs not really meant for volume production gerbers that are created by CAD software are usually ok. If you're going for high volume, then some postprocessing software will be needed. Examples of such software would be FAB3000, CAM350, Pentalogix. This way you can design very complex panel arrangements, tooling holes, transform pad shapes (you would be amazed by how much you can reduce assembly errors with clever paste shape). You can also design variants of PCBs with different components assembled (for example DPAK in place of D2PAK) or some of them not assembled at all -by removing unnecessary openings you save solder paste.

It's typically PCB designer who is responsible for SMT stencil engineering, not assembly process engineer.

[JuKu]

I'll hijack this thread a bit. How do one design stencils?

In Altium, the stencil openings are part of the part definition, on their own layer. Of course, you can edit stuff on that layer too, just like any other layer. And you send the Gerbers of that layer along with the rest of the data. Nothing more in it. (Although as poorchava said, it can be a complex subject of its own.) Normally, the default solder mask and stencil definitions are just fine.

I would think that any other package has similar concept.

[Rundstedt]

It's typically PCB designer who is responsible for SMT stencil engineering, not assembly process engineer.

The thing is at the moment I am both, I'm responsible from designing schematic, through pcb design, code, production and probably quality control procedures.

[poorchava]

Do you work for some kind of startup/small business? What you say is actually not the best approach if your company is aiming at any serious electronics production.